Electronic systems typically require the ability to enable, disable, or modify certain functions of an integrated circuit (“IC”) chip after the IC has been manufactured. Such customization or modifications are typically achieved through blowing electronic fuses formed on the ICs. The fuses may include a silicided polysilicon conductor that is blown by directing a current of sufficient magnitude and duration through the fuse to melt or electromigrate at least a portion of the silicide between the first and second ends of the fuse.
Sense amplifiers are implemented with fuses for sensing the state of an fuse, i.e., a high resistance state when the fuse is blown and a low resistance state when the fuse is unblown or intact. However, the performance of the sense amplifier cannot be independently characterized in silicon and may only be characterized through simulations, which are not always accurate due to variances in process, voltage, and temperature (“PVT”). Consequently, the sensing margin of the sense amplifier may not be accurately determined through simulations resulting in poor performance of the IC. For example, if the resistance of a blown fuse is 5 kΩ and the resistance of an intact fuse is 200Ω, then the sense amplifier will accurately read data if the sense amplifier trip point for a “read high” state is less than 5 kΩ and the trip point for a “read low” state is greater than 200Ω. However, if the sense amplifier has a trip point for a read high that is above 5 kΩ or a trip point for a read low that is below 200Ω, then the data cannot be accurately read.